Improving an exact approach for solving separable integer quadratic knapsack problems

We consider the specially structured (pure) integer Quadratic Multi-Knapsack Problem (QMKP) tackled in the paper “Exact solution methods to solve large scale integer quadratic knapsack problems” by D. Quadri, E. Soutif and P. Tolla (2009), recently appeared on this journal, where the problem is solved by transforming it into an equivalent 0–1 linearized Multi-Knapsack Problem (MKP). We show that, by taking advantage of the structure of the transformed (MKP), it is possible to derive an effective variable fixing procedure leading to an improved branch-and-bound approach. This procedure reduces dramatically the resulting linear problem size inducing an impressive improvement in the performances of the related branch and bound approach when compared to the results of the approach proposed by D. Quadri, E. Soutif and P. Tolla.     

Egalitarianism and utilitarianism in committees of representatives

We consider a committee of representatives that makes dichotomous choices (acceptance/rejection) by vote. Given the size of each group represented, what is the most adequate voting rule for the committee? We provide answers based on each of the two principles commonly used to make normative assessments in different contexts: egalitarianism and utilitarianism. To that end, we introduce utilities into the model and adopt a normative approach.     

Educating for Practice in the Chicano Community

This paper conveys one perspective on the development and implementation of a training curriculum designed within a framework of knowledge, values, and skills essential for compatible and complementary social work practice in the Chicano community. It reflects the theoretical foundations upon which the Chicano Training Center is constructing a continuing education program for social service and mental health personnel. Curriculum content areas and emphases, as well as training modalities, are discussed and suggested as possible means for educating practitioners to better understand and serve Mexican Americans. The development of bicultural practice models in service delivery systems is also stressed.     

THE LABOR MARKET IN THE ART SECTOR OF BAROQUE ROME

We analyze the labor market for painters in Baroque Rome using unique data on primary sales of portraits, still lifes, genre paintings, landscapes, and figurative paintings. In line with the traditional artistic hierarchy of genres, average price differentials between them were high. The matched painter‐patron nature of the dataset allows us to evaluate the extent to which price heterogeneity is related to unobservable characteristics of painters and patrons. We find that the market allocated artists between artistic genres to the point of equalizing the marginal return of each genre. Residual price differences at the employer level can be explained in terms of incentive mechanisms to induce effort in the production of artistic quality and compensating wage differentials. (JEL C23, D8, J3, Z11)     

IDENTIFYING THE SOURCES OF LOCAL PRODUCTIVITY GROWTH

Using firm‐level based TFP indicators (as opposed to employment‐based proxies) we estimate the effects of alternative sources of dynamic externalities at the local level. In contrast to previous empirical work, we find that industrial specialization and scale indicators affect TFP growth positively, while neither product variety nor the degree of local competition have any effect. Employment‐based regressions yield nearly the opposite results, in line with most of previous empirical work. We argue that such regressions suffer from serious identification problems when interpreted as evidence of dynamic externalities. Our results question the conclusions of most of the existing literature on dynamic agglomeration economies. (JEL: R11, O47)     

Reducing waiting times in the Italian NHS: The case of Emilia-Romagna

In 2015, the Emilia-Romagna Regional Government implemented a plan to reduce waiting times for elective outpatient procedures. The objective set by the regional government establishes that at least 90 per cent of specialist services are to be provided within the following maximum waiting times: 30 days for the first specialist consultation, and 60 days for diagnostic tests. The plan adopted by the Emilia-Romagna Regional Government is of particular interest because it encompasses a combined strategy. Some of the interventions envisaged in the plan aim at increasing the supply of specialist services. Others address the demand side, seeking to reduce inadequate requests and discourage no-shows by patients. And others focus on combining supply and demand and neutralizing the effects of some perverse incentives. The Emilia-Romagna plan appears to have had a successful outcome. In the first 4 years of implementation, the 90 per cent target has not only been achieved but also widely exceeded.     

Comparative analysis of emergency department patients lost to follow-up after computerized alcohol screening and brief intervention

Many studies have evaluated the effectiveness of alcohol screening and brief intervention (SBI) but most of them have reported substantial loss to follow-up without investigating the characteristics of those lost to follow-up. We examined the association between Alcohol Use Disorders Identification Test (AUDIT) scores, readiness-to-change scores and the demographic factors with lost to follow-up. This retrospective study compared demographic characteristics, AUDIT and readiness-to-change scores for 190 lost to follow-up patients to 221 completed follow-up patients who participated in SBI in the Emergency Department between June 2006 and May 2007. Comparing the association between baseline characteristics and completed follow-up rate, those 30–39, 40–49 and 50 years and older had 0.46 (95% CI 0.32–0.91), 0.49 (95% CI 0.29–0.90) and 0.58 (95%CI 0.22–0.79) lower odds of completing follow-up, respectively, in comparison to those 18–29 years of age. The loss to follow-up group reported more negative consequences of alcohol and binge drinking than the completed follow-up group (p = 0.04). Using logistic regression, patients who experienced more negative effects of alcohol had 0.87 lower odds of completing follow-up (95% CI 0.79–0.96). The patients lost to follow-up in this study were significantly different in age and alcohol drinking habits compared to those completed follow-ups. It is important to consider differential loss to follow-up in assessing the validity and generalizability of intervention studies. This could help in tailoring methods of approaching patients based on target population characteristics.     

PSS business model conceptualization and application*

The discussion about business models has gained considerable attention in the last decade. Business model frameworks have been developed in the literature as management methods helping companies to comprehend and analyse their current business logic and guide the deployment of new strategies. In response to calls for a deeper understanding of the application of a business model approach to product-service systems (PSS), this study develops a two-level hierarchical framework that (i) includes a set of components with pertinent, second-order variables to take into account when undergoing the shift from products to solutions; (ii) supports industrial companies, especially SMEs, in designing their future business model and in consistently planning the actions needed to implement it. The framework was applied and refined within real-life settings. The application to KINE – a robot solutions supplier – shows how key challenges faced by servitization firms may be thoroughly addressed through the adoption of a business model perspective.     

Improving innovation performance through environmental practices in the fashion industry: the moderating effect of internationalisation and the influence of collaboration

In recent years, the scientific literature on supply chain management has increasingly debated on environmental sustainability as well as collaboration, presenting these issues as an important source of innovation along the supply chain. By combining literature streams on environmental sustainability, supply chain collaboration and innovation at the supply chain level, this paper aims to analyse whether the adoption of environmental sustainability practices and collaboration along the supply chain implies better innovation performance, in terms of differentiation from the competitors for higher quality, product or process. The paper also investigates whether the internationalisation, in terms of both production and distribution activities, negatively moderates this relationship. The study focuses on the fashion industry, and a survey of major Italian fashion companies was conducted. The main results of the research clearly show the positive impact of these practices on innovation performance. The paper also proves the existence of a moderating effect exerted by internationalisation on the relationship between environmental sustainability and innovation performance.